Fire ecology
Fire ecology

Start this free course now. Just create an account and sign in. Enrol and complete the course for a free statement of participation or digital badge if available.

4.1 Fire and ecological succession

Early successional communities establish themselves relatively quickly after a fire (rapid colonisers) while late successional communities establish themselves much later (Figure 21).

The diagram shows six stages of ecological succession starting on the left and proceeding to the right. Time is represented by a horizontal arrow from left to right. Each stage of succession is illustrated by a drawing of the type of vegetation that would be found at that stage. At the first stage there is bare rock, at the second stage there are mosses and grasses, at the third stage there are grasses and perennials, at the fourth stage woody pioneers are in evidence, at the fifth stage fast-growing trees have appeared; at the sixth and final stage there is a climax forest. Above the drawings of the six stages are a series of lines depicting the increase in abundance of habitat as the stages proceed so that at the first stage, bare rock predominates with no vegetation present. This is gradually replaced by mosses and grasses at stage 2 and then at stage 3 grasses and perennials appear, followed by woody plants, fast-growing trees and then larger trees. So, at stage 6 the climax forest consists of a complex mixture of vegetation.
Figure 21  Diagrammatic representation of forest succession over time. There is a steady increase in biodiversity, biomass and thickness of soil layer as succession proceeds, i.e. as time passes.

Although fires open up gaps for early successional communities, community composition – the number and diversity of species present – is profoundly affected by the fire regime, and in particular its frequency and/or intensity.

For example, if fires are frequent the community will be dominated by early-succession, opportunistic, fast-colonising, resistant species because species characterising later successional stages will not be able to become established before the next fire.

  • What kind of community would be expected if fires are rare?

  • The community tends to be dominated by a few highly competitive, late-succession species. These species outcompete earlier-colonising species and can become established before the next fire.

Take your learning further

Making the decision to study can be a big step, which is why you'll want a trusted University. The Open University has 50 years’ experience delivering flexible learning and 170,000 students are studying with us right now. Take a look at all Open University courses.

If you are new to University-level study, we offer two introductory routes to our qualifications. You could either choose to start with an Access module, or a module which allows you to count your previous learning towards an Open University qualification. Read our guide on Where to take your learning next for more information.

Not ready for formal University study? Then browse over 1000 free courses on OpenLearn and sign up to our newsletter to hear about new free courses as they are released.

Every year, thousands of students decide to study with The Open University. With over 120 qualifications, we’ve got the right course for you.

Request an Open University prospectus371